1. Field of the Invention
This invention provides compounds having drug and bio-affecting properties, their pharmaceutical compositions and method of use. In particular, the invention is concerned with new diazaindole derivatives that possess unique antiviral activity. More particularly, the present invention relates to compounds useful for the treatment of HIV and AIDS.
2. Background Art
HIV-1 (human immunodeficiency virus-1) infection remains a major medical problem, with an estimated 42 million people infected worldwide at the end of 2002. The number of cases of HIV and AIDS (acquired immunodeficiency syndrome) has risen rapidly. In 2002, ˜5.0 million new infections were reported, and 3.1 million people died from AIDS. Currently available drugs for the treatment of HIV include ten nucleoside reverse transcriptase (RT) inhibitors or approved single pill combinations (zidovudine or AZT (or Retrovir®), didanosine (or Videx®), stavudine (or Zerit®), lamivudine (or 3TC or Epivir®), zalcitabine (or DDC or Hivid®), abacavir succinate (or Ziagen®), Tenofovir disoproxil fumarate salt (or Viread®), Combivir® (contains −3TC plus AZT), Trizivir® (contains abacavir, lamivudine, and zidovudine) and Emtriva® (emtricitabine); three non-nucleoside reverse transcriptase inhibitors: nevirapine (or Viramune®), delavirdine (or Rescriptor®) and efavirenz (or Sustiva®), nine peptidomimetic protease inhibitors or approved formulations: saquinavir, indinavir, ritonavir, nelfinavir, amprenavir, lopinavir, Kaletra® (lopinavir and Ritonavir), Atazanavir (Reyataz®), Fosamprenavir® and one fusion inhibitor which targets viral gp41 T-20 (FUZEON®). Each of these drugs can only transiently restrain viral replication if used alone. However, when used in combination, these drugs have a profound effect on viremia and disease progression. In fact, significant reductions in death rates among AIDS patients have been recently documented as a consequence of the widespread application of combination therapy. However, despite these impressive results, 30 to 50% of patients ultimately fail combination drug therapies. Insufficient drug potency, non-compliance, restricted tissue penetration and drug-specific limitations within certain cell types (e.g. most nucleoside analogs cannot be phosphorylated in resting cells) may account for the incomplete suppression of sensitive viruses. Furthermore, the high replication rate and rapid turnover of HIV-1 combined with the frequent incorporation of mutations, leads to the appearance of drug-resistant variants and treatment failures when sub-optimal drug concentrations are present (Larder and Kemp; Gulick; Kuritzkes; Morris-Jones et al; Schinazi et al; Vacca and Condra; Flexner; Berkhout and Ren et al; (Ref. 6-14)). Therefore, novel anti-HIV agents exhibiting distinct resistance patterns, and favorable pharmacokinetic as well as safety profiles are needed to provide more treatment options.
Currently marketed HIV-1 drugs are dominated by either nucleoside reverse transcriptase inhibitors or peptidomimetic protease inhibitors. Non-nucleoside reverse transcriptase inhibitors (NNRTIs) have recently gained an increasingly important role in the therapy of HIV infections (Pedersen & Pedersen, Ref 15). At least 30 different classes of NNRTI have been described in the literature (De Clercq, Ref. 16) and several NNRTIs have been evaluated in clinical trials. Dipyridodiazepinone (nevirapine), benzoxazinone (efavirenz) and bis(heteroaryl)piperazine derivatives (delavirdine) have been approved for clinical use. However, the major drawback to the development and application of NNRTIs is the propensity for rapid emergence of drug resistant strains, both in tissue cell culture and in treated individuals, particularly those subject to monotherapy. As a consequence, there is considerable interest in the identification of NNRTIs less prone to the development of resistance (Pedersen & Pedersen, Ref 15). A recent overview of non-nucleoside reverse transcriptase inhibitors: perspectives on novel therapeutic compounds and strategies for the treatment of HIV infection. has appeared (Buckheit, reference 99). A review covering both NRTI and NNRTIs has appeared (De Clercq, reference 100). An overview of the current state of the HIV drugs has been published (De Clercq, reference 101).
Several indole derivatives including indole-3-sulfones, piperazino indoles, pyrazino indoles, and 5H-indolo[3,2-b][1,5]benzothiazepine derivatives have been reported as HIV-1 reverse transciptase inhibitors (Greenlee et al, Ref. 1; Williams et al, Ref. 2; Romero et al, Ref. 3; Font et al, Ref. 17; Romero et al, Ref. 18; Young et al, Ref. 19; Genin et al, Ref. 20; Silvestri et al, Ref. 21). Indole 2-carboxamides have also been described as inhibitors of cell adhesion and HIV infection (Boschelli et al, U.S. Pat. No. 5,424,329, Ref. 4). 3-Substituted indole natural products (Semicochliodinol A and B, didemethylasterriquinone and isocochliodinol) were disclosed as inhibitors of HIV-1 protease (Fredenhagen et al, Ref. 22).
Structurally related aza-indole amide derivatives have been disclosed previously (Kato et al, Ref. 23(a); Levacher et al, Ref. 23(b); Dompe Spa, WO-09504742, Ref. 5(a); SmithKline Beecham PLC, WO-09611929, Ref. 5(b); Schering Corp., U.S. Pat. No. 05,023,265, Ref. 5(c)). However, these structures differ from those claimed herein in that they are monoaza-indole mono-amide rather than oxoacetamide derivatives, and there is no mention of the use of these compounds for treating viral infections, particularly HIV.
New drugs for the treatment of HIV are needed for the treatment of patients who become resistant to the currently approved drugs described above which target reverse transcriptase or the protease. One approach to obtaining these drugs is to find molecules which inhibit new and different targets of the virus. A general class of inhibitors which are under active study are HIV entry inhibitors. This general classification includes drugs aimed at several targets which include chemokine receptor (CCR5 or CXCR4) inhibitors, fusion inhibitors targeting viral gp41, and inhibitors which prevent attachment of the viral envelope, gp120, the its human cellular target CD4. A number of reviews or general papers on viral entry inhibitors have recently appeared and some selected references are:    Chemokine receptor antagonists as HIV entry inhibitors. Expert Opinion on Therapeutic Patents (2004), 14(2), 251-255.    Inhibitors of the entry of HIV into host cells. Meanwell, Nicholas A.; Kadow, John F. Current Opinion in Drug Discovery & Development (2003), 6(4), 451-461.    Virus entry as a target for anti-HIV intervention. Este, Jose A. Retrovirology Laboratory irsiCaixa, Hospital Universitari Germans Trias i Pujol, Universitat Autonoma de Barcelona, Badalona, Spain. Current Medicinal Chemistry (2003), 10(17), 1617-1632.    New antiretroviral agents. Rachline, A.; Joly, V. Service de Maladies Infectieuses et Tropicales A, Hopital Bichat-Claude Bernard, Paris, Fr. Antibiotiques (2003), 5(2), 77-82.    New antiretroviral drugs. Gulick, R. M. Cornell HIV Clinical Trials Unit, Division of International Medicine and Infectious Diseases, Weill Medical College of Cornell University, New York, N.Y., USA. Clinical Microbiology and Infection (2003), 9(3), 186-193.    Sensitivity of HIV-1 to entry inhibitors correlates with envelope/coreceptor affinity, receptor density, and fusion kinetics. Reeves, Jacqueline D.; Gallo, Stephen A.; Ahmad, Navid; Miamidian, John L.; Harvey, Phoebe E.; Sharron, Matthew; Pohlmann, Stefan; Sfakianos, Jeffrey N.; Derdeyn, Cynthia A.; Blumenthal, Robert; Hunter, Eric; Doms, Robert W. Department of Microbiology, University of Pennsylvania, Philadelphia, Pa., USA. Proceedings of the National Academy of Sciences of the United States of America (2002), 99(25), 16249-16254. CODEN: PNASA6 ISSN: 0027-8424.    Opportunities and challenges in targeting HIV entry. Biscone, Mark J.; Pierson, Theodore C.; Doms, Robert W. Department of Microbiology, University of Pennsylvania, Philadelphia, Pa., USA. Current Opinion in Pharmacology (2002), 2(5), 529-533.    HIV entry inhibitors in clinical development. O'Hara, Bryan M.; Olson, William C. Progenics Pharmaceuticals, Inc., Tarrytown, N.Y., USA. Current Opinion in Pharmacology (2002), 2(5), 523-528.    Resistance mutation in HIV entry inhibitors. Hanna, Sheri L.; Yang, Chunfu; Owen, Sherry M.; Lal, Renu B. HIV Immunology and Diagnostics Branch, Division of AIDS, STD, Atlanta, Ga., USA. AIDS (London, United Kingdom) (2002), 16(12), 1603-1608.    HIV entry: are all receptors created equal? Goldsmith, Mark A.; Doms, Robert W. Genencor International, Inc., Palo Alto, Calif., USA. Nature Immunology (2002), 3(8), 709-710. CODEN: NIAMCZ ISSN: 1529-2908.    Peptide and non-peptide HIV fusion inhibitors. Jiang, Shibo; Zhao, Qian; Debnath, Asim K. The New York Blood Center, Lindsley F. Kimball Research Institute, New York, N.Y., USA. Current Pharmaceutical Design (2002), 8(8), 563-580.
A series of recent publications and disclosures characterize and describe a compound labelled as BMS-806, an initial member of a class of viral entry inhibitors which target viral gp-120 and prevent attachment of virus to host CD4.    A small molecule HIV-1 inhibitor that targets the HIV-1 envelope and inhibits CD4 receptor binding. Lin, Pin-Fang; Blair, Wade; Wang, Tao; Spicer, Timothy; Guo, Qi; Zhou, Nannan; Gong, Yi-Fei; Wang, H.-G. Heidi; Rose, Ronald; Yamanaka, Gregory; Robinson, Brett; Li, Chang-Ben; Fridell, Robert; Deminie, Carol; Demers, Gwendeline; Yang, Zheng; Zadjura, Lisa; Meanwell, Nicholas; Colonno, Richard. Proceedings of the National Academy of Sciences of the United States of America (2003), 100(19), 11013-11018.    Biochemical and genetic characterizations of a novel human immunodeficiency virus type 1 inhibitor that blocks gp120-CD4 interactions. Guo, Qi; Ho, Hsu-Tso; Dicker, Ira; Fan, Li; Zhou, Nannan; Friborg, Jacques; Wang, Tao; McAuliffe, Brian V.; Wang, Hwei-gene Heidi; Rose, Ronald E.; Fang, Hua; Scarnati, Helen T.; Langley, David R.; Meanwell, Nicholas A.; Abraham, Ralph; Colonno, Richard J.; Lin, Pin-fang. Journal of Virology (2003), 77(19), 10528-10536.    Method using small heterocyclic compounds for treating HIV infection by preventing interaction of CD4 and gp120. Ho, Hsu-Tso; Dalterio, Richard A.; Guo, Qi; Lin, Pin-Fang. PCT Int. Appl. (2003), WO 2003072028A2.    Discovery of 4-benzoyl-1-[(4-methoxy-1H-pyrrolo[2,3-b]pyridin-3-yl)oxoacetyl]-2-(R)-methylpiperazine (BMS-378806): A Novel HIV-1 Attachment Inhibitor That Interferes with CD4-gp120 Interactions. Wang, Tao; Zhang, Zhongxing; Wallace, Owen B.; Deshpande, Milind; Fang, Haiquan; Yang, Zheng; Zadjura, Lisa M.; Tweedie, Donald L.; Huang, Stella; Zhao, Fang; Ranadive, Sunanda; Robinson, Brett S.; Gong, Yi-Fei; Ricarrdi, Keith; Spicer, Timothy P.; Deminie, Carol; Rose, Ronald; Wang, Hwei-Gene Heidi; Blair, Wade S.; Shi, Pei-Yong; Lin, Pin-fang; Colonno, Richard J.; Meanwell, Nicholas A. Journal of Medicinal Chemistry (2003), 46(20), 4236-4239.
Indole, azaindole and other oxo amide containing derivatives have been disclosed in a number different PCT and issued U.S. patent applications (Reference 93-95, 106, 108, 109, 110, 111, 112, 113, and 114). None of these applications discloses diazindole compounds such as described in this invention. The extra nitrogen of the diazaindole class of molecules provides altered properties especially in combination with specific substituents that are advantageous and not available from the azaindoles. The diazaindoles are easier to access and thus offer the potential to provide patients with lower cost treatments. A series of PCT International Patent applications Bernd Nickel et. al. (reference 107a,b, and c) describes N-indolylglyoxamides for the treatment of cancer. Although some of these compounds contain N-heteroaryl or N-aryl piperazines, the substitution patterns at the other positions are outside the scope of this invention.
Structurally similar diazaindoles with a C-3 oxoacetyl group have also been previously disclosed (Hutchison et al, Ref 5(d); Resnyanskaya et al, Ref 24 (a); Cook et al, Ref 24(b)). However, these molecules differ from those claimed in that they do not contain the piperazine or piperidine moieties and there is no mention of the use of these molecules as antiviral agents, particularly against HIV.
Nothing in these references can be construed to disclose or suggest the novel compounds of this invention and their use to inhibit HIV infection.